Reconstructed internal combustion engine cylinder heads and method of making same



MORRISON 3,187,729 NAL c BUSTION ENGINE CYLINDER METH OF MAKING SAME E. NTER AND June 8, 1965 RECONSTRUCTED I HEADS 2 Sheets-Sheet 1 Filed Dec. 3, 1965 III/I I lune s, 1965 o so $187,729 INIV'ER RECONSTRUCT NAL COMBUSTION G CYLINDER H S AND METHOD OF MAKI SA Filed Dec. 3, 1963 2 Sheets-Sheet 2 z O 3s 47 46 41 Q INVENTOR A 27 r-Edwm'dMkrnifon BY ATTORNEY tent Fatented dune 8, 1965 3 137 729 RENSTRUCTEE QGMBUSTEGN EIJGHIE C LENDER HEADS ANE) ME' HU'D OF hiAlGNG SAPEE Edward Morrison, New Rochelle, N.Y., assighor to Raiph This invention relates to reconstructed internal cornbustion engine cylinder heads, and is directed both to the structure of the repaired head and the method of effecting the reconstruction.

It is a common occurrence for the cylinder heads of such engines, particularly those with fuel injectors like diesel engines-always subject to continuous operative stresses under high pressure and temperature conditionsto become subject to metal fatigue and develop fissures in the region of the fuel injector unit, such cracks frequently occurring in the cylinder head wall between the aperture housing said unit and the inlet and/ or outlet valve apertures. The repair of such damaged heads involves the removal of the cracked portions and threaded wall of the aperture through which the fuel injector extends and then the rebuliding of said threaded Wall. The

conventional method of doing this is first machining out the damaged and adjacent stock with a suitable tool to produce an enlarged cavity, then burning out any remaining damaged portions with an city-acetylene torch, and thereafter progressively welding in a suitable metal such as a grey cast iron weld adapted for operative use with cast iron cylinder material. This Welding process involves a progressive building up of the mass of weld material within the cavity until it is solidly filled with said material. Thereafter, a hole is drilled through the solidified welded mass and a thread formed to accommodate the fuel injection unit.

It has been found that the repaired cylinder head structure resulting from the above-described conventional method has serious shortcomings. Because of the inherent nature of the said Welding-filling process, the material suitable for this process is too soft and porous to satisfactorily perform its structural function in a diesel cylinder head over extended periods of time. Experience indicates that, during the Welding process, air pockets form within the mass of the tiller material, resulting in the formation of blow holes therein under the prevailing temperature-pressure conditions, and thereby causing leakage of water from the adjacent water jackets and consequent serious engine damage. Another disadvantage of the use of the conventional relatively soft welded mass is that it often cannot withstand the high torque, in the neighborhood of 275 lbs., required for installing the externally threaded fuel injector so that it will not be dislodged by the high operative pressures within the cylinder. It has been found that in attempting to screw in the injector with sufficient force, the threads of the. apertured portion accommodating the injector are often stripped. Still another shortcoming of the conventional welded-mass construction above described is the inability of this material to serve as a sufiiciently hard and leakproof seat for the precombustion chamber of the fuel injection unit, the relative softness of this material causing it to deform under pressure and subjecting the said unit to the danger of displacement from its optimum position and the development of leaks.

It is an object of my invention to provide a method of repairing cylinder heads of the above category so as to produce a head having none of the aforesaiddisadvantages. repaired diesel cylinder heads that are free of air pockets More specifically, my objectives are to produce at the critical region adjacent the injector-receiving aper-. ture and thereby to eliminate the damage of water leaks, to provide a structure of sutficient strength to enable it to withstand the required torques for installing the injector unit and to rigidly support the unit in pl cc, and to provide a hard, non-deformable, accurately ground and thoroughly sealed seat for said precombustion chamber.

And it is within my contemplation to provide a relatively inexpensive and readily effected method of producing repaired cylinder heads having the aforesaid features.

Other objects, features and advantages will appear from the d-rar ings, and the description hereinafter given.

In the drawings,

FIG. 1 is a fragmentary bottom perspective view of a damaged diesel engine cylinder head prior to repair and reconstruction in accordance with the method and structure of my invention.

FIG. 2 is a somewhat enlarged fragmentary bottom view of a portion of the cylinder head of FIG. '1.

PEG. 3 is an enlarged fragmentary section of FIG. 2 taken along line 3-3, showing a conventional fuel injector unit with precombustion chamber operatively in place. 7

FIG. 4 is an enlarged sectional representation of a portion of the cylinder head shown in FIG. 3, the injector unit having been removed in accordance with the preliminary first step of the method of my invention.

KG. 5 is a fragmentary section like FIG. 4 but showing the illustrated cylinder head portion after the removal of the preconihustion chamber seat and the damaged stock by a machining operation in accordance with a step in the method of my invention.

FIG. 6 is a side e-levational View of a form of plug member employed in the practice of the invention.

PEG. 6a is a top view of FIG. 6.

F163. 7 to 11 inclusive are fragmentary sections like FIG. 5 illustrating successive steps in the method of my invention in producing the reconstructed cylinder head portion illustrated in FIG. 11.

FIG. 12 is a fragmentary sectional view of the portion of the cylinder head shown in FIG. 3, illustrating the reconstructed portion operatively accommodating the fuel injector precombustion chamber unit.

Referring to the drawings, the fragment of the damaged cylinder head 15 illustrated in FIG. 1 shows three sections thereof designated as regions A, B and C adapted for coactive positioning with respect to correspondingly positioned cylinders on a cylinder block not shown. Each of these sections has intake and exhaust valve ports and an apertured portion foroperatively accom-' modating a fuel injector, all in accordance with structures well known to those skilled in the art. For purposes of this specification. only the sectionin region B, as indicated in FIG. 2, will be considered, inasmuch as the'application of my invention to the reconstruction times hereinafter referred to as the inner wall since it is adapted for engagement with the cylinder block,'-the latter being hereinafter referred to as the outer Wall since it is exposed to the atmosphere. stood that more extensive fissured portiond such as fissures extending from apertured portion'18 to either or It is to be under- 3 a both the valve portions 16 and 17, can be reconstructed in accordance with the method hereinbelow described as applied to the said fissure 19.

In the conventional structure shown in FIG. 3, the said apertured portion 18 extends from the said face 2i? through the said inner wall 22 to the face 23 of the boss 24, the internal wall of the apertured portion 18 being threaded along the extent thereof. Welded to said boss 24 is the centrally apertured seat 25. The fuel injector unit 27 comprises the inner fuel injecting portion 23 and the precombustion chamber 29-the said portion 28 being in threaded engagement with the threaded wall of the apertured portion 13, the said chamber 29 having a shoulder 30 in abutting engagement with the surface 31 of said seat 25, the opposite outer end 32 of the chamber 29 extending through the aperture 33 in the said outer wall 34 supporting the sealing ring 35 in annular engagement with the said end 32 of chamber 29}. The said respective intake and exhaust ports 16 and 17 are in operative communication with the respective passage ways 36 and 37 in known manner.

In practicing the method of my invention, the injector unit 27 is first operatively removed; and then the ringlike seat 25,'shown in FIG. 4 as still attached, is removed by any means known to those skilled in the art. Thereafter, by means of a suitable machine tool, the damaged stock of wall 22 around the apertured portion 18 is removed, this operation resulting in the formation of an enlarged aperture 38 extending from the said face 20 to the water-jacket surface 39, the said aperture being of greater diameter at said face 29 than at said surface 39.

The next step in the provision of plug 44 (FIGS. 6 and 60) made of hard, closely .grained and compact metal, preferably cast iron. This plug, according to its preferred configuration, comprises a frustro-conical body portion 41 and, in axial alignment therewith, a cylindrical boss 42 at the wider end of the body portion, forming an annular shoulder 43 with an outside diameter defined by the periphery 44 at the base of said frustroconical portion 41. In the preferred proportions of the plug, the altitude of the conical portion 41 is substantially equal to the thickness of wall 22 of the cylinder head between the said surfaces 29 and 39, and the diameter of the said periphery 44 is no less, and preferably a trifle greater, than the diameter of the annular edge 45 of said apertured portion 38.

The said plug is placed within the said apertured portion 38 with the periphery 44 ofthe plug resting upon the Wall of the apertured portion adjacent to or at the said annular edge 45, the boss 42 extending outwardly beyond said surface 39. The arrangement is such as to form an annular cavity 46 around the plug.

Itshould here be noted that a cylinder head having a number of damaged regions is subjected to the same steps as above described, plugs 40 being inserted in all apertured portions analogous to portions 38 and formed in like manner.

The cylinder head 15 with the plug orplugs 4%) in place is then preheated to a predetermined temperature, a satisfactory temperature for the material used in my process being 1600 F. Thereafter, using suitable welding material, the annular juncture J of the said periphery 44 of the plug and the annular edge of the apertured portion 38 is fused to form a seal separating the cavity 46 from the water jacket 26 into which the plug said boss 42 extends (see FIG. 12). An annular ring of sealing weld material 47 is then applied, as shown in FIG. 8. The rest of the cavity is then filled by the welding material, this material being gradually built up by awelding process known to those skilled, in the art to form a solid mass 48 around the plug, as shown in FIG. 9.

After a suitable interval to permit coolingand setdrilled through the plug and reamed, andthen a counteri sunk portion 5% is formed in the boss 42 to form a seat 51 therein, as illustrated in FIG. 10. Thereafter, the wall of the drilled hole 49 is threaded to form a threaded annular wall 52 as shown in FIG. 11. The repaired portion of the cylinder head is now in its fully reconstructed form, ready to receive the fuel injector unit 27.

FIG. 12 illustrates the fuel injector unit 27 operatively positioned in the reconstructed portion of the cylinder head 15. Portion 28 of said unit is in threaded engagement with said internally threaded Wall 52 of the plug 40; and since the plug is solid and made of hard compact material, as aforesaid, the threads of the plug will not be subject to stripping during the screwing in of the injector and affixing it in place with the required torque. This results in a firm immovable securernent of the injector unit to the cylinder head, without the danger of a deformation of threads of the wall supporting the injector, or of the aforesaid stripping of such threads, thereby obviating the danger of leakage of water from the jacket into the cylinder a is possible with the above described conventionally repaired structure in which the injector unit is in threaded engagement with a mass of relatively soft weld material.

It will be noted that the shoulder 30 of the precombustion chamber portion 29 is in abutting engagement with the seat 53. in the boss 42-said seat being made of the above-mentioned hard and compact material. This seat, properly ground, provides a firm and leak-proof seat for the fuel injector unit, and supplements the structural support provided for the injector unit by the relatively hard internally threaded wall 52 of the plug. The annular juncture I of the plug 40 and wall 22, having been fused,

as above described, provides a seal against leakage in this region. The mass of weld material 48, being out of contact with any portion of the wall 21 defining the water jacket, cannot transmit any water from the jacket 22 to the cylinder, even if said mass 43 has air pockets therein; and since the plug 40 is of such compact structure that no air pockets are contained therein, there is no danger of leakage of water from the jacket through the material of the plug or through the remote weld material 48.

In the above description, the invention has been disclosed merely by way of example and in preferred manner; but obviously many variations and modifications may be made therein. It is to be understood, therefore, that the invention is not limited to any form or manner of practicing same, except insofar as such limitations are specified in the appended claims.

I claim:

1. In a reconstructed internal combustion engine cylinder head having a water jacket and being adapted for operative threaded engagement with a threaded fuel injector unit having an intermediate annular shoulder, said head having an inner wall adjacent and defining a side of said jacket, a plug of hard compact material extending through said inner wall and having a boss in facing relation to said water jacket, a threaded apertured portion extending through said plug and proportioned for operative threaded engagement with said fuel injector unit, said boss having an annular seat proportioned and positioned for operative engagement with said annular shoulder of said injector unit when said unit is in operative threaded engagement with said apertured portion of said plug, said plug being welded to the body of said inner wall.

2. In a reconstructed internal combustion. engine cylirider head, the combination according to claim 1, said boss extending into said water jacket and having a recessed portion therein, said annular seat being disposed within said recessed portion, and welding material joining the lateral surface of said plug outside of said boss to the adjacent body portion of said inner wall.

3. In a reconstructed internal combustion engine cylinder head, the combination according to claim 1, the portion of said plug adjacent said- Water jacket having an e9 annular shoulder defined by the outer periphery of said plug and the outer surface of said boss, said boss extending into said water jacket and having a recessed portion therein, said annular seat being disposed within said recessed portion, and welding material joining the lateral surface of said plug from its said outer periphery to the opposite edge thereof to the adjacent body portion of said inner wall.

4. In a reconstructed diesel engine cylinder head having a water jacket and being adapted for operative threaded engagement with a threaded fuel injector unit having an intermediate annular shoulder, said head having an inner wall defined by a face adapted for engagement with the cylinder block of said engine and an interior surface defining a side of said water jacket, a plug of hard compact material extending through said inner wall and having a frustro-conical body portion, a threaded apertured portion extending through said plug and proportioned for operative threaded engagement with said fuel injector unit, said plug having an annular seat in facing relation to said water jacket and proportioned and positioned for operative engagement with said annular shoulder of said injector unit when said unit is in operative threaded engagement with said apertured portion of said plug, and welding material joining the lateral surface of said frustro-conical body portion to the adjacent body portion of said inner Wall.

5. In a reconstructed diesel engine cylinder head, the combination according to claim 4, said plug having a cylindrical boss at the Wider end of said frustro-conical body portion and in axial alignment therewith, said boss extending into said water jacket and having therein said annular seat.

6. In a reconstructed diesel engine cylinder head, the combination according to claim 4, said plug having a cylindrical boss at the wider end of said frustro-conical body portion and in axial alignment therewith, said boss extending into said water jacket and having therein said annular seat, said boss being of lesser diameter than the periphery of said frustro-conical portion at said wider end thereof, whereby an annular shoulder is formed on said plug defined by said periphery and the annular wall of said boss, the altitude of said frustro-conical portion being substantially equal to the thickness of said inner wall.

7. In a reconstructed diesel engine cylinder head having a water jacket and being adapted for operative threaded engagement with a threaded fuel injector unit having an intermediate annular shoulder, said head having an inner wall defined by a face adapted for engagement with the cylinder block of said engine and an interior surface defining a side of said water jacket, an apertured portion in said inner wall extending from said face to said interior surface thereof and defining a plug cavity, a plug of hard compact material disposed within said cavity and having an annular seat in facing relation to said water jacket, a threaded apertured portion extending through said plug and proportioned for operative threaded engagement with said fuel injector unit, said annular seat being proportioned and positioned for operative engagement with said annular shoulder of said injector unit when said unit is in operative threaded engagement with said apertured portion of said plug, and welding material within said cavity and joining the lateral surface of said plug to the adjacent body portion of said inner wall.

8. In a reconstructed diesel engine cylinder head having a water jacket and being adapted for operative threaded engagement with a threaded fuel injector unit having an intermediate annular shoulder, said head having an inner wall defined by a face adapted for engagement with the cylinder block of said engine and an interior surface defining a side of said water jacket, an apertured portion in said inner wall extending from said face to said interior surface thereof and defining a plug cavity, said cavity being wider at said face than at said interior surface, a plug of hard compact material extending through said inner wall and having a frustro-conical body portion, a threaded apertured portion extending through said plug and proportioned for operative threaded engagement with said fuel injector unit, said plug having an annular seat in facing relation to said water jacket and proportioned and positioned for operative engagement with said annular shoulder of said injector unit when said unit is in operative threaded engagement with said apertured portion of said plug, the periphery of said frustroconical body portion at its wide end being in resting engagement with the peripheral portion of the wall defining said cavity in the region of said interior surface of the inner wall, whereby the engaging portions of said plug and cavity wall form a peripheral seal between said water jacket and said cavity, and welding material Within said cavity and joining the lateral surface of said plug to the adjacent body portion of said inner Wall.

S In a reconstructed diesel engine cylinder head, the combination according to claim 8, said plug having a cylindrical boss in axial alignment therewith, in circumferentially spaced relation to said peripheral seal and extending into said water jacket, said boss having therein said annular seat.

ift. In a method of reconstructing a jacketed diesel engine cylinder head having an inner Wall adjacent the jacketed portion and containing a threaded apertured portion adapted for supporting engagement with a threaded fuel injector unit having an intermediate annular shoulder, said wall having a cracked portion therein in the region of said threaded apertured portion, the steps of removing a predetermined portion of the stock of said inner wall which includes said cracked portion, fonming a cavity in said wall extending from the face of said well at the cylinder side thereof to the opposite interior surface defining a side of said jacketed portion, providing a plug of hard compact material, inserting said plug into said cavity, welding the plug to the adjacent body portion of the inner wall, drilling a hole through the plug from the engine end thereof to the water jacket end, forming anannular seat at the base of the plug in facing relation to said jacket and proportioned for operative engagement with said annular shoulder of the injector unit, and threading the wall defining said drilled hole for operafive threaded engagement with the fuel injector when in operative engagement with said seat,

11. In a method of reconstructing a jacketed diesel engine cylinder head having an inner Wall adjacent the jacket-ed portion and containing a threaded apertured poltion adapted for supporting engagement with a threaded I fuel injector unit having an intermediate annular shoulder,

said wall having a cracked portion therein in the region of said threaded apertured portion, the steps of removing a predetermined portion of the stock of said inner wall which includes said cracked portion, forming a cavity in said Wall extending from the face of said wall at the cylinder side thereof to the opposite interior surface defining a side of said jacketed portion, said cavity being wider at said face than at said interior surface, providing a plug of hard compact material and having a fru'stroconical body portion with a periphery at the base thereof proportioned for resting engagement with the peripheral portion of the wall of said cavity in the region of said interior surface of said inner wall, inserting said plug into said cavity with the peripheral portion of the base thereof resting upon said peripheral portion of the Wall of the cavity, whereby the engagingportions of the plug and cavity wall form a peripheral seal between said water jacket and said cavity,'welding the, plug to the adjacent body portion of said inner Wall, drilling a hole through the plug from the engine end thereof to the Wa-- t er jacket end, forming an annular seat at the base of the plug in facing relation to said jacket and proportion-ed for operative engagement with said annular shoulder of the '7 injector unit, and threading the wall defining saiddrilled hole for operative threaded engagement with the fuel in jector when in operative engagement with said seat.

1 2. In a method of reconstructing a jacketed diesel engine cylinder head having an inner wall adjacent the jacketed portion containing a threaded apertured portion adapted for supporting engagement with a threaded fuel injector .unit having an intermediate annular'shoulder, said wall having a cracked portion therein in the region of said threaded apertured portion, the steps of removing -a predetermined portion of the stock of said inner wall Which includes said cracked portion, forming of the base thereof resting upon said peripheral portion of the wall of the cavity, whereby the engagement portions of the plug and cavity Wall form a peripheral seal between said water jacket and said cavity, preheating the cylinder head with the plug therein to a predetermined temperature, fusing together the said engaging portions .of the plug and cavity wall to form a fused peripheral seal, welding the plug along its frustro-conica-l lateral surface to the surrounding cavity wall and filling in said cavity with Welding material, drilling a hole through the plug from the engine end thereof to the-water jacket end, forming an annular seat at the base of the plug in facing relation to said jacket and proportioned for operative engagement With said annular shoulder of the inject-or unit, and threading the wall. defining said drilled hole for operative threaded engagement with the fuel injector when in operative engagement with said seat.

13. In :a method of reconstructing a jacketed internal combustion engine cylinder head having an inner wall adjacent the jacketed portion and containing an apertured portion adapted for supporting engagement with a fuel injector unit, said wall having a cracked portion therein in the region of said apertured portion, the steps of removing a predetermined portion of the stock of said inner wall which includes said cracked portion, forming a cavity in said wall extending from the face of said wall at the cylinder side thereof to the opposite interior surface defining a side of said jacketed portion, providing a plug of hard compact material, inserting said plug into said cavity, welding the plug to the adjacent body portion of the inner wall, and drilling a hole through the plug from the engine end thereof to the water jacket end for operative engagement with said fuel injector.

References Cited by the Examiner UNITED STATES PATENTS 2,949,901 8/ 60 Spencer et al 12-341.82 3,062,614 11/ 62 Stanclitf et a1 123-4182 3,077,187 2/63 Stancliif et al 1234l.82

RICHARD B. WILKINSON, Primary Examiner. 

1. IN A RECONSTRUCTED INTERNAL COMBUSTION ENGINE CYLINDER HEAD HAVING A WATER JACKET AND BEING ADAPTED FOR OPERATIVE THREADED ENGAGEMENT WITH A THREADED FUEL INJECTOR UNIT HAVING AN INTERMEDIATE ANNULAR SHOULDER, SAID HEAD HAVING AN INNER WALL ADJACENT AND DEFINING A SIDE OF SAID JACKET, A PLUG OF HARD COMPACT MATERIAL EXTENDING THROUGH SAID INNER WALL AND HAVING A BOSS IN FACING RELATION TO SAID WATER JACEKT, A THREADED APERTURED PORTION EXTENDING THROUGH SAID PLUG AND PROPORTIONED FOR OPERATIVE THREADED ENGAGEMENT WITH SAID FUEL INJECTOR UNIT, SAID BOSS HAVING AN ANNULAR SEAT PORTIONED AND POSITIONED FOR OPERATIVE ENGAGEMENT WITH SAID ANNULAR SHOULDER OF SAID INJECTOR UNIT WHEN SAID UNIT IS IN OPERATIVE THREADED ENGAGEMENT WITH SAID APERTURED PORTION OF SAID PLUG, SAID PLUG BEING WELDED TO THE BODY OF SAID INNER WALL. 